Circuit controller



Feb. 10, 1942. AYERS 2,272,763

CIRCUITCONTROLLER Filed Nov 28, 1940 Fig.

g y INSULATION Fig.2. 4o

INSULATION i v F g 42 40 l5 INSULATION Irwventor: Edgar H. Ayers,

His Attorney.

Patented Feb. 10, 1942 CIRCUIT CONTROLLER Edgar H. Ayers, Schenectady,N. Y., assignor to General Electric Company, a corporation of New YorkApplication November 28, 1940, Serial No. 367,560

11 Claims.

My invention relates to circuit controllers and more particularlytoseries rtype circuit controllers adapted to be used as starting relaysin connection with split-phase alternating current motors.

In starting circuits for split-phase motors it is known to use a seriesrelay having an operating coil in the running circuit and controlcontacts in the starting circuit of the motor. The motor starting relayof this type most common-ly used heretofore comprises an operatingWinding connected in series with the running circuit of the motor and apair of normally open contacts connected in series with the startingcircuit of the motor. In operation, the high starting current traversingthe motor running winding energizes the relay, causing it to completethe motor starting winding circuit through the relay control contacts.As the motor comes up to speed and the current diminishes in value therelay is unable to maintain its armature picked up. When the armaturedrops out it opens the starting circuit of the motor and the motorcontinues to run on its running winding only.

It will be observed that, in the type of starting relay described above,the relay contacts are designed to be closed when the relay coil isenergized; thus ordinary mechanical design therefore indicates that therelay contacts would be open when the relay coil is deenergized. Withsuch an arrangement it is necessary that the relay contacts, in closing,make a starting current which may be many times the normal operatingcurrent of the motor. The presence of such a high current upon closingof the contacts tends to cause the contacts to weld together andproduces numerous other undesirable and deleterious results, as will beevident to those skilled in the art.

While these difficulties may be overcome by the use of a shunt-connectedor voltage responsive relay having normally closed starting contacts,the use of a shunt relay is undesirable from a cost standpoint. It will'be readily understood that the expense necessarily incurred in theWinding of a shunt coil having many turns of very fine wire is fargreater than that incurred in the winding of a series coil formed ofrelatively large wire and having only a small number of turns.Furthermore, the voltage type relay in its present form is basicallynoiser than the current responsive type of relay.

Accordingly, it is an object of my invention to provide a series typecircuit controller having normally closed control contacts.

It is a further object of my invention to provide a series type circuitcontroller having normally closed control contacts arranged to remainclosed upon full energization of the controller and to I tudinal wallll.

open upon subsequent partial deenergization of the controller.

Further objects and advantages of my invention will be apparent, and theinvention itself will be better understood, from the followingdescription taken in conjunction with the accompanying drawing; and thefeatures which I be lieve to be novel and patentable will be pointed outwith particularity in the appended claims. In the drawing Fig. 1represents a top view of a controller embodying my invention; Fig. 2 isa front elevational View of Fig. 1 showing the controller in itsdeenergized position; Fig. 3 is a front elevational view of thecontroller in its partially energized position; and Fig. 4 is a circuitdiagram of connections for a controller embodying my invention appliedto a typical splitphase motor starting circuit.

Referring now to the drawing, I have shown my invention in one form asapplied to a starting controller for a split-phase motor of the typefrequently employed in a refrigeration system. However, it will beobvious that my invention has broad application to motors requiringspecial starting means. The controller is mounted on a base i0 formed ofsuitable insulating material and having a vertically projecting longi-The upper edge of the Wall ll serves as a support for a substantiallyU-shaped magnetizable frame l2 fixed to the wall H by rivets in and it!)or other suitable fastening means. The frame I2 is bent edgewise and hasa core portion extending through the center of a current responsiveoperating Winding l3 and terminating in a pole piece it. Electricallyconnected to the frame l2 by a lead Wire [6 is a terminal l5 fixed inthe base it. Positioned in spaced attractive relationship to the polepiece it is an armature ll of magnetizable material mounted upon acantilever spring l9 and carrying a resilient contact member 20. Inorder to dampen oscillations of the armature H which might be producedby the alternating character of the electromotive force supplied to thecoil [3, I have provided short circuited windings 2! attached to theupper end of the armature I'l. As is well understood in the art, thedamping effect of the short circuited windings H is due mainly to theout-of-phase flux produced by the circulating current induced in thewindings by the changing flux in the core member I2. Thecantilever'spring i9 is fixedly attached at one end to the magnetizableframe l2 by any suitable means such as a rivet 22. The resilient member23 carries a control contact 23 and, together with the armature I1 andthe cantilever spring l9, constitutes a pivotally mounted movable memberoperative in response to energization of the pole piece M.

Biased into engagement with the control contact 23 is a contact 24mounted upon one end of a cantilever spring 25. The opposite end of thecantilever spring 25 is fixedly attached to a portion of the insulatingbase I!) by any suitable means such as an internally threaded rivet 2G.The rivet 26, together with the bolt 21 cooperating therewith,constitutes another terminal of my controller. Referring now to theoperating winding I3, this winding is connected at one end to themagnetizable frame [2 by any suitable means such as a welded connection28; and the other end of the winding 13 is connected by a lead 29 to aterminal 30 fixed in the base For engaging the resilient movably mountedcontact member 25 I have shown a latch member 35 pivoted on a pin 33 andincluding at its lower extremity a latch 31. Though the pin 36 may beattached to any convenient support, it is shown in the drawing as weldedto the magnetizable frame l2. The latch member 35 is biased intoengagement with the contact member 25. As clearly shown in Figs. 2 and3, the latch member 35 is biased by the location of its own center ofgravity to rotate in a clockwise direction. It will be understood, ofcourse, that if desired the bias of the latch member toward the contactmember 25 may be obtained by any other suitable means, such as a spring.As clearly shown in Figs. 2

and 3, the latch 31 is provided with two notches 1- 3B and 39, the notch38 engaging the contact member 25 when the armature I1 is in itsdeenergized position, and the notch 39 engaging the contact member 25when the armature I1 is in its fully energized position or its partiallyen- 2 ergized position as shown in Fig. 3. Mounted upon the armature I!I have shown a tripping member 40 carrying a tripping pin 4!. Thetripping pin M is adapted to engage the substantially horizontal portion42 of the latch member 35 when the armature I1 is in its deenergizedposition.

Referring now to Fig. 4, I have shown a schematic diagram of asplit-phase alternating current motor comprising a running winding 45and a starting winding 46 connected to alternating current lineconductors 4'! and 48 through the winding 13 and the contacts 23 and 24of my circuit controller. The electrical circuit through my circuitcontroller, schematically indicated in Fig. 4, may now be followed onFigs. 1, 2, and 3. The line conductor 41 is connected to the terminal15; and the running circuit for the motor may be followed from theterminal I through the lead wire it, the magnetizable frame l2, theconnection 28, the series winding I3, the lead 29 and the terminal 30 tothe running winding 45 of the motor, and from the running winding 45 tothe line conductor 48. From the terminal I5 of the controller thestarting circuit may be traced through the lead wire IS, themagnetizable frame l2, the cantilever spring IS, the contact member 20,the contacts 23 and 24, the contact member 25 and the terminalconnection 26 to the starting winding 45 of the motor, and from thestarting winding 45 to the line can ductor 48.

In operation, when the line switch ii! of Fig. 4 is closed a highstarting current traverses both the running winding 45 and the startingwinding 46 of the motor and passes through the series winding [3 of thecircuit controller. The high current flowing through the winding [3attracts the armature I! from its deenergized position shown in Fig. 2to its fully energized position (not shown) in which the armature H isdirectly opposite the pole face M. In the fully energized position ofthe controller the contact member 25 and the contact 24 have beendeflected by the movable contact member to a position in which themovably mounted resilient contact member engages the notch 39 of thelatch 31. It will be borne in mind that in this position the contacts 23and 24 are still in engagement. As the motor, thus set into operation,begins to come up to speed the motor current diminishes in value untilit is insufiicient to hold the armature ll of the controller in itsfully energized position. The armature I"! then falls back to someintermediate position, such as that shown in Fig. 3. In the intermediateposition shown in Fig. 3 the tripping pin 41 has not yet engaged theportion 42 of the tripping member 35, but the contact 23 has beensufliciently retracted to separate it from the latched contact 2%. Inthis position the starting winding 45 of the motor i opened at thecontacts 23 and 24 and the motor is operating on its running winding 45alone.

If new the line switch 43 of Fig. i is opened, the motor runningcircuit, including the series winding it will be completely deenergizedand the armature ii will drop out and assume its initial position shownin Fig. 2. In falling back to its deenergizcd position the tripping pin4! attached to the tripping member 4 engages the portion 13 of the latchmember causing the latch member to rotate in a counter-clockwisedirection and release the resilient contact member from the notch 39.Upon release the resilient contact member 25 springs upward, bringingthe contact 24 again into engagement with the movable contact andengaging the notch 38 of the latch 37. In the deenergized position shownin Fig. 2 the latch member 35 determines the position of both thearmature H carrying the contact member 2b and the position of theresilient contact member 25. It will be observed that engagement of theresilient member 25 with the notch 38 of the latch 31 tends to rotatethe latch member 35 in a clockwise direction, while engagement of thetripping pin 4! with the latch member 35 tends to rotate the latchmember 35 cotmterclockwise. Thus, the contact member 25, biasing thelatch member 35 clockwise, holds the arm 42 of the latch member againstthe tripping pin 4! attached to the armature IT and thereby positionsthe armature. The contact member 223 is of suflicient resilience tomaintain the contacts 23 and 24 in engagement in the deenergizedposition shown.

While I have illustrated and described only one preferred embodiment ofmy invention, many modifications will occur to those skilled in the art;and I, therefore, wish to have it understood that I intend by theappended claims to cover all such modifications as fall within the truespirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is:

1. In a circuit controller, a movable member carrying a first contactand having two spaced limiting positions, a movably mounted contactmember resiliently biased into engagement with said first contact,latching means engaging said movably mounted contact member when saidmovable member is in one of said limiting positions, and tripping meansmounted on said movable member and engaging said latching means whensaid movable member is in said other limiting position.

2. In a circuit controller, a movable member carrying a first contactand having two limiting positions, a movably mounted contact memberresiliently biased into engagement with said first contact, latchingmeans biased into engagement with said movably mounted contact memberand engageable therewith when said movable member is in one of saidlimiting positions to hold said contacts out of engagement while saidmovable member is in any intermediate position, and tripping meanscarried by said movable member and engaging said latching member whensaid movable member is in said other limiting position.

3. In a circuit controller, a movable mem er carrying a contact andhaving two spaced limiting positions, a movably mounted contact memberresiliently biased into following engagement with said contact, latchingmeans engaging said movably mounted contact member when said movablemember is in one of said limiting positions, and tripping means carriedby said movable member and engaging said latching means when saidmovable member is in said other limiting position.

4. In a circuit controller, a pivotally mounted movable member carryinga first contact and having two spaced limiting positions, a fixedlymounted cantilever spring carrying at its free end a second contact,said cantilever spring biasing said second contact into followingengagement with said first contact, a pivotally mounted latch memberengaging said cantilever spring when said movable member is in one ofsaid limiting positions, and a tripping finger mounted on said movablmember and engaging said latching member when said movable member is insaid other limiting position.

5. In a circuit controller, a magnetic frame, a magnetic armaturecarrying a first contact and movable with respect to said frame from adeenergized to an energized position, a coil for magnetizing said frameand said armature, a contact member carrying a second contact biasedinto following engagement with said first contact, latch means engagingsaid contact member when said armature is in its energized position, andtripping means engaging said latching means when said armature is in itsdeenergized position.

6. In a circuit controller, a magnetic frame, a magnetic armaturecarrying a first contact and movable with respect to said frame from adeenergized to an energized position, a coil for magnetizing said frameand said armature, a resiliently mounted contact member carrying asecond contact biased into following engagement with said first contact,latch means engaging said resiliently mounted contact member when saidarmature is in its energized position, and tripping means mounted uponsaid armature engaging said latching means when said armature is in itsdeenergized position.

7. In a circuit controller, a magnetic frame, a pivotally mountedmagnetic armature carrying a first contact and movable with respect tosaid frame from a deenergized to an energized position, a coil formagnetizing said frame and said armature, a resiliently mounted contactmember carrying a second contact biased into following engagement withsaid first contact, a pivotally mounted latch member biased intoengagement with said contact member and engaging said contact memberwhen said armature is in said energized position, and tripping meansmounted upon said armature and engaging said latching member when saidarmature is in said deenergized position.

8. In a circuit controller, a magnetic frame, a pivotally mountedmagnetic armature carrying a first contact and movable with respect tosaid frame from a deenergized to an energized position, a currentcarrying coil embracing said frame in magnetizing relation with saidframe and said armature, a fixedly mounted resilient cantilever springcarrying at its free end a second contact biased into followingengagement with said first contact, a pivotally mounted latching memberbiased into engagement with said cantilever spring and engaging saidcantilever spring when said armature is in said energized position, anda tripping finger carried by said armature and engaging said latchingmember when said armature is in said deenergized position.

9. In a circuit controller, a resiliently mounted armature biased to afirst limiting position, a first contact mounted upon said armature, amovably mounted contact member biased into engagement with said firstcontact, means for moving said armature and said contact member to asecond limiting position spaced from said first position, and latchmeans for retaining said contact member in said second position untilsaid armature returns to said first position.

10. In a circuit controller, an insulating support, a magnetic framemounted upon said support, a first cantilever spring having one endmounted upon said frame, a magnetic armature mounted upon the free endof said first spring and having an end movable with respect to saidframe from a deenergized to an energized position, a first contactresiliently mounted upon said armature, a current carrying coilembracing said frame in magnetizing relation to said frame and armature,a second cantilever spring carrying at its free end a second contactbiased into following engagement with said first contact, a pivotallymounted latching member biased into engagement with said secondcantilever spring and engaging said spring when said armature is in saidenergized position, and a tripping finger carried by said armature andengaging said latching member when said armature is in said deenergizedposition.

11. In a circuit controller, a movable member carrying a movable contactand having a predetermined normal position, a second contact resilientlybiased into following engagement with said movable contact and arrangedto control a first circuit, latch means for retaining said secondcontact out of engagement with said movable contact, means responsive toa predetermined high current in a second circuit to actuate said movablemember to move said second contact to latching position while saidcontacts remain engaged, said means being arranged to return saidmovable contact to an intermediate position upon a diminution of saidcurrent thereby to disengage said contacts, and trip means actuated bysaid movable member upon return of said member to said normal positionfor releasing said latch means thereby to permit said second contact toreengage said movable contact.

EDGAR H. AYERS.

